Fuel injection device for internal combustion engines



H. DINNER 1,918,324

FUEL INJECTION DEVICE FOR INTERNAL COMBUSTIONENGINES July 18, 1933.

Filed March 8, 1932 Ink/ENTER:

a ,W EEJ? 7 EM UM Q WTWM'\* Patented July 18, 1933 UNITED STATES PATENT OFFICE HEINRICH DINNER, osmium; SWITZERLAND, AssIGNort'ro THE FIRM SULZER rnEREs SOCIETE ANONYME, F WINTERTHURM SWITZERLAND .FUEI; INJECTION DEVICE FOR INTERNAL COMBUSTION ENGINES Application filed March 8, 1932, Serial 110. 597,436, and in Switzerland March 2 5, 1931.

This invention .relates to upwardly directed fuel injection devices for internal combustion engines; engines of that kind in which the fuel is injected into the cylii1-,

6 der together with air.

to be injected is stored prior to each injection in a preliminary storage chamber usually disposed some distance below the needle 10 valve seating so that, before injection air is contained between the storage chamber and the seating whereby when the needle valve begins to open this air alone passes into the cylinder before actual injection of the fuel commences. Ignition is in this way undesirably retarded not only on account of the delay which takes place before actual injectionbut-also on account of the fact that the air, injected before the fuel, tends to reduce the temperature of that air which has been compressed in the engine cylinder. With a view to overcoming this difficulty it has been proposed to introduce fuelthrough the seating surface of the needle valve without air immediately the valve begins to open and then to inject the remainder of the fuel mixed with air. This however tends to result in the fuel which is first injected being insufiiciently atomized so that ignition is delayed, whilst in addition the fuel is liable to burn explosively and thus cause shocks which may prove injurious to the engine. The present invention has for its object to overcome the abovedifiicult-ies. According to the present invention the fuel is introduced above the level of a preliminary storage chamber so as to pass under the action of gravity over surf-aces by which partof the fuel is retained, whereby when 40 the needle valve begins to open the air contained between the preliminary storage chamber and the needle valve seating together with the fuel retained by the said surfaces are injected in the. form of a mixture into the engine cylinder. Preferably the fuel is introduced from a supply chamber or conduit at a level above' thatof the storage chamber which lies below the needle valve seating, an intermediate structure arranged between the seating and storage may be introduced from the supply cham In injection devlces of this type the fuel' cause part of the fuel to be retained thereby.

chamber being such that a portion of the fuel is retained by parts of this structure as the fuel passes under the action of gravity towards the storage chamber. The fuel :ber or conduit through passages directed towards the valve seating so as to flow over the intermediate structurewhich is conveniently recessed or provided with grooves to In the accompanying drawing Figure 1 is a fuel injection curve for injection devices of known type, the air curve being shown in full whilst the fuel curve is dotted, 1

Figure 2 illustrates in a similar manner the injection of fuel in accordance with the invention, and

Figure 3 shows, by way of example, and in longitudinal section, one construction of in jection device according. to the invention.

In known typesof fuel injection devices when the fuel needle valve be ins to open at a (Figure 1) either the a1r contained between the preliminary storage chamber and the needle valve seating is injected into the cylinder without fuel (as shown in full lines), or when a preliminary quantity of fuel is introduced through the seating surface of the valve, this fuel enters the cylinder without 'air. The desired mixture of fuel and air'is therefore in eithercase injected only after a delay which is indicated in Figure 1 by the-distance, a, b and-injection'is thus delayed, the needle valve closing at c. i

The full line curve in Fig. 1 represents the rate of injection of the air per unit of time, the dotted-line curve the rateof injection of the fuel per unit of time. The ordinates are a measure 'of the amount of air and/or fuel, the abscissa representing the time of injection. Hence, the injection of fuel mixed with air into the workingcylinder in Fig. 1 only commences at point I); Fig. 1 relates to known embodiments in which air enters the cylinder first, without fuel. In arrangements where thetfuel is injected in the seat of .the needle itself and the bulk of the fuel is injected without mix- 100 ing with the air as soon as the needle valve is raised, the dotted curve would start at a and the full-line curve at b.

With an injection device according to the present invention, however, and as hereinat e. In this way the valve seating is-free of'fuel which at the end of fuel injection may be adhering thereto whereby carbonlzation, which is more particular y liable to take place when the fuel is of inferior qualpass through the bor away the fuel in the recess 11 before injectity, is .reduced to a minimum; One construction of fuel injection device according to the invention forobtaining this result is illustrated in Figure 3 in which the needle valve 1 cooperates with a seating 2,

' a'valve casing 3 carrying the nozzle head4.

5 which is screwthreaded tq'eengage a conical ring 7 having bores 6, the ring 7 bearing against a second'ring 9 similarly furmshed with bores '8 and bearing in turn on a tubuin this way gripped between the ring 7 and the guide 5.

so constructed that the cooperate to form a I preliminary storage c amber for the fuel comprising two annular recesses 11 and "12, the axial cross-sectional area oftherecess that-of the recess '12 is u shapeda's shown; Anannular air supply conduit 13 communi- 'cates with onearm ofthe u shaped recess and in the axial direction with the recess direction with: the shaped'recess 12.

Fuel is fed through conduit 14 i to an annular fuelsupply. chamber 15 from which trapped in the, grooves17' an also adheres to the surfaces of the rings and the internal Hsurfaces'of the bores 6 and 8. A further portion of the fuel becomes lodged in the recess 11 whilst the rest flows downward into the recess 12.

When'the injection deviceis in operation and the needle valve is closed fuel is "supplied under pressure through the conduit 14 to the annular chamber 15 from.which' it passes'through the passages 16 V and runs over the rings 7 and 9. When the needle the cylinder and ignition is-.not delayed.

The needle valve 1 is movable within a guide l ar member 10 which rests on the. guide 5. I The ring 9 and the tubularmember 10 arev The tubular member- 10. and guide 5 are ,11 being substantially rectangular whilst which in rn ommunicates in the radial-- other arm of the the fuel passes throughipassag'es 16 directed 7and 9 is] between the valve seating 2 and'the recesses- 11 and 12 forms a mixture with the fuel retained bythe rings 7 and 9 and is injected. .Thus, immediately the needle valve commences to open finely atomized fuel is injected through the nozzle 18 into the cylind'er. The injection air thereupon first carriesthe fuel contained in the recess 11 through the valve seating, whereupon the fuel in the recess 12 is atomized and injected.

It will be seen that since the fuel contained in the inner arm of the U-shaped recess 12 acts, in effect, as a back pressure on that contained in the outer arm, the air entering through the c nduit 13 will first 19 so as to carry kingthat in the recess 12.- The arrangement is such that the needle valve 1 remains open after all the fuel in the recesses 11 and 12 has been injected so that after injection of the fuel has been completed, any fuel adhering to the valve seating 2 and injection orifice 18 is swept away, the tendency for being thereby reduced.

It will be understood that the construction above described is given by way of example only and that details may be modi- 'fied withont departing from the spirit of cylinder, the combination with a needle valve of. a preliminary fuel storage chamber below the level of the valve seating, a

, carbonization-to take place at these parts chamber or conduit from which fuel is in- Jtroduced above the level of the preliminary chamber, a structure between the seating and preliminary chamber such that a portion of the fuel is retained by parts of this structure as the fuel passes under the action 1 of'gravity towards the preliminary chamber, and an air supply conduit commu- 'mcating -with the preliminary chamber for the purpose set forth. v

In a, fuel injection device asclaimed in claim -1 the arrangement, that the fuel is introduced from an annular supply chamher through passages directed towards the valveseating.

3. In'afuel injection device as claimed in 'claim ql the arrangement, that the surfaces of the structure over which the fuel has to pass on its way to the preliminary chamber are recessed to cause part of the fuel to be retained thereby.

, 4; In a fuel. injection device as claimed in claim 1 the arrangement, that the surfaces of the structure over which the fuel claim 1, a preliminary storage chamber comprising two annular recesses the axial cross- 5. In a fuel injection device as claimed in sections of'which are substantially rectangular and U-shaped respectively, an air supply conduit communicating w1th one arm of the U-shaped recess and also with the rectangular recess which in turn communicates with the other arm of the U-shaped recess.

HEINRICH DINNER. 

